INDIANAPOLIS — The owner of a house that exploded in Indianapolis, killing two people and damaging dozens of homes so severely officials say they must be demolished, said Monday that a problem furnace could be at fault.

John Shirley, 50, of Noblesville, told The Associated Press that his daughter sent him a text message last week complaining that the furnace in the home where she lives with her mother and her mother's boyfriend had gone out and required them to stay at hotel.

But Shirley also said when he asked if the furnace had been fixed, his daughter said yes, and he wasn't aware of any additional problems until he heard from his daughter again Sunday morning.

"I get a text from my daughter saying 'Dad, our home is gone. Then I called my ex-wife and she said what happened," he said.

His ex-wife, Monserrate Shirley, declined to comment Monday.

Investigators said they have not determined a cause for the Saturday night blast that sparked a massive fire, blew out windows, collapsed ceilings and shook homes up to three miles away. Public Safety Director Troy Riggs said the search for answers could take some time.

Utility workers have been inspecting gas mains in the neighborhood but so far have detected no leaks, a spokesman said.

The blast forced about 200 people out of their homes in the once-tidy neighborhood of one- and two-story single-family houses.

Some were allowed to return Sunday, and others were able to retrieve a few belongings. But those whose homes suffered the most damage will never be allowed back inside, officials said. They have estimated about 30 homes will need to be demolished.

Indianapolis code enforcement officials met Monday with homeowners at a nearby church to discuss insurance and demolition procedures and to make arrangements to take some to their homes for an hour to collect more belongings later in the day.

The blast flattened the house Shirley co-owns with his ex-wife and one next door that belongs to second-grade teacher Jennifer Longworth and her husband, John. The coroner's office has not yet identified the two people killed in the blast, but a candlelight vigil was held Sunday night at the school where Jennifer Longworth teaches.

Indiana real estate records show Shirley's house had been for sale for a year until it was taken off the market in March.